In 3GPP (The 3rd Generation Partnership Project, The 3rd Generation Partnership Project) standards, a thorough research has been made on a SON (Self-Organized Network, self-organized network), which is a major characteristic of the LTE (Long Term Evolution, Long Term Evolution). A SON is a decentralized network formed by a group of mobile terminal nodes with wireless transceiver devices, a network system capable of rapid deployment and use without depending on existing infrastructure of fixed communication networks, and a self-organizing and self-healing network without any central entities. All network nodes coordinate with each other to perform communication and exchange information through wireless links, thereby implementing sharing of information and services. In the network, two nodes incapable of direct communication may perform packet forwarding be means of other nodes to form a multi-hop communication mode. In a SON, capacity and coverage are two major functions of the SON and capacity and coverage compromise with each other. The main object of the SON is to maximize system capacity while guaranteeing network coverage.
In the prior art, several solutions in the following are adopted to implement the object.
Solution 1: A vertical sectorization method. One cell is divided into an inner cell and an outer cell and each cell is covered at a different antenna downtilt. The inner cell and the outer cell share the original cell power and multiplex the cell bandwidth. Therefore, the system capacity may be optimized through the linear gain of bandwidth multiplexing.
Solution 2: An algorithm for distributed pilot power adjustment. In the algorithm, two different time periods, a large time period and a small time period, are taken into consideration, in which one large time period is formed of a plurality of small time periods. Within a small time period, each cell adjusts pilot power frequently and rapidly based on load information. The load information includes the load information of a current cell and the load information of neighboring cells. Within a time period, each cell adjusts pilot power slowly.
During the implementation of optimizing capacity and coverage of a network, the inventor finds that the prior art at least has the following problems: Solution 1 mainly implements the adjustment of capacity and coverage for a single cell but fails to consider the coverage hole and coverage overlap problems of the entire network; and in Solution 2, each cell is required to know the load information of neighboring cells, thereby increasing the signaling exchange load of a system.